1,720,998 research outputs found
Thermodynamic basis for vapor solubility in ethyl cellulose
No full textThe solubility of several gases and vapors in glassy ethyl cellulose (EC) over wide ranges of temperature
and pressure is described by means of a thermodynamic model, which specifically accounts for the
nonequilibrium volumetric properties of EC. The behaviors of polymer/penetrant mixtures are repre-
sented by the well-established nonequilibrium lattice fluid model (NELF) in its latest development,
suitable to be used in a pure predictive fashion for the representation of the volume swelling of the
polymer matrix, as induced by penetrant sorption. The analysis reveals the ability of the model to
describe all the experimental trends, and a sole binary parameter for each polymer/penetrant couple is
considered. The NELF model allows the satisfactory prediction of the thermodynamic properties of all
polymer/solute systems examined, in the entire range considered for temperature and vapor fugacity
Predictive model for gas and vapor solubility and swelling in glassy polymers I: Application to different polymer/penetrant systems
No full textAn extensive analysis is performed for the use of a model recently introduced for sorption induced volume dilation in glassy polymers, which can be combined with the nonequilibrium lattice fluid model (NELF) for the description of gas and vapor solubility in glassy polymers in a wide temperature range below the glass transition, from dry to fully plasticized conditions. The procedure extends the capability of previous versions of NELF model, as it refers to correlation and prediction of solubility of vapors and swelling agents. To this aim, the model counts on an additional out-of-equilibrium parameter for the polymeric species that interprets its pseudoequilibrium compressibility, and it can be retrieved from the analysis of pure component pressure–volume–temperature data below Tg. The examples discussed in this work show that the overall procedure is highly reliable and addresses the key properties of the system for the direct interpretation of the effect of temperature, solute fugacity and state of glassy polymers on pseudoequilibrium volume swelling and solute content
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
pVT Data Analysis for the Prediction of Vapor Sorption in Glassy Polymers through the Nonequilibrium PC-SAFT Model
No full textThe first implementation is presented for the Restrained
Swelling
(RS) version of the Nonequilibrium Thermodynamics for Glassy Polymers
(NET-GP) approach, which counts on the PC-SAFT EoS to express the
equilibrium properties of polymer-solute mixtures. Examples for application
of the resulting model (NE-RS) PC-SAFT to the prediction of gas and
vapor solubility in conventional glassy polymers are first discussed.
Emphasis is put on the role of pVT properties for pure polymer species,
as measured at both melt and glass conditions. The first application
is then presented for the NE-RS approach to the analysis of gas and
vapor solubility data in a polymer with intrinsic microporosity, for
which pVT data in the melt phase cannot be measure and reliable values
for the volumetric properties at glassy conditions are not available.
In the latter analysis, both kinds of pVT properties are eventually
retrieved from the best fit of the selected solubility data and the
result for the polymer pVT characteristics are finally compared with
those recently presented in the literature as obtained after the use
of “Dry Glass Reference Perturbation Theory“ (DGRPT),
within the same NET-GP approach
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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